The ruins of the keep stand on a hilltop dominating the town. This formidable tower was probably erected by Robert I de Meulan († 1118), lord of Brionne, to replace an older fortification situated on an islet of the Risle in the heart of the town, which had suffered two sieges in 1047 and 1090. In 1124, the new tower was besieged by Henri I, Beauclerc against Galeran de Meulan, son of Robert.
The tower is in the interior of a small circular arc-shaped earth enceinte, which could correspond to one of two redoubts constructed by William the Bastard during his first siege of Brionne in 1047, the second was probably the enceinte of the same type seen on the edge of the opposite hill, north west of the town. The keep, originally seen as a solid 20 metre square building, with 4 metre thick walls supported by buttresses, has only one and a half sides left standing. The surviving masonry, conserved to a height of 17 metres, is very interesting from an archaeological point of view. The construction was separated into three floors, a blind ground floor, a windowed first floor and a high upper room covered by a two-sided roof of which traces are still visible on the interior surface facing. The protruding stones on the western wall show, on the first floor, the remains of a Romanesque fireplace embedded in the masonry. On the external facing of the northern wall, near the summit, can be seen a series of large quadrangular holes, thought to be traces of supports for wooden hoarding.
Jacques Le Maho
- A. Chatelain, Donjons romans des pays d’Ouest, Paris, 1973, p. 115-116